排序方式: 共有22条查询结果,搜索用时 15 毫秒
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层次分析法在基础选型中的应用 总被引:2,自引:0,他引:2
在综合考虑影响高层建筑基础选型各种因素的基础上,建立了基于层次分析法的基础选型数学模型,通过量化计算,可得出适用的基础选型方案。通过一工程实例,验证了运用层次分析法进行基础选型的有效性与合理性。 相似文献
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Hepatoprotective effect of Cassia obtusifolia seed extract and constituents against oxidative damage induced by tert‐butyl hydroperoxide in human hepatic HepG2 cells 下载免费PDF全文
Md Yousof Ali Susoma Jannat Hyun Ah Jung Byung‐Sun Min Pradeep Paudel Jae Sue Choi 《Journal of Food Biochemistry》2018,42(1)
The aim of the present study was to investigate the hepatoprotective effects of different soluble fractions of methanolic derived Cassia obtusifolia seeds extract (COE) and its active components in tert‐butyl hydroperoxide (t‐BHP)‐induced oxidative stress in HepG2 cells. Among the tested fractions, the ethyl acetate (EtOAc) fraction was the most active hepatoprotective fraction. From the active EtOAc fraction, six anthraquinones (alaternin, emodin, aloe emodin, 2‐hydroxyemodin 1‐methyl ether, chryso‐obtusin‐2‐O‐β‐d ‐glucoside, and questin) and one naphthopyrone glycoside (cassiaside) were isolated. The cytotoxic effect in 200 µM t‐BHP‐induced HepG2 cells was inhibited by COE and their bioactive compounds. The protective effect of COE in 200 µM t‐BHP‐induced HepG2 cells may be associated with positive regulation of glutathione (GSH) and decreased in reactive oxygen species (ROS) formation of their bioactive compounds. The increased ROS and decreased GSH levels observed in t‐BHP‐treated HepG2 cells were ameliorated by pretreatment with cassiaside, alaternin, and aloe emodin, indicating that the hepatoprotective effects of these major constituents are mediated by induction of cellular defense against oxidative stress. Overall, COE displayed a significant cytoprotective effect against oxidative stress, which may most likely be because of active compounds like cassiaside, alaternin, and aloe emodin in COE, which leads to maintenance of the normal redox status of cells.
Practical applications
The dried and roasted seeds of Cassia obtusifolia are commonly consumed as brew tea and medicinal foods in Korea. The seeds have multiple therapeutic actions related to the treatment of liver disease, dementia, diabetes, eye inflammation, photophobia and lacrimation, dysentery, headache, as well as dizziness. The present study demonstrates the hepatoprotective effect through prevention of oxidative stress, suggesting that C. obtusifolia and its constituents may have beneficial effects in preventing hepatic diseases. 相似文献4.
Mehdi Mehrpooya Ali VataniS.M. Ali Mousavian 《Chemical Engineering and Processing: Process Intensification》2010
In this study a novel process configuration for recovery of hydrocarbon liquids from natural gas is proposed. The required refrigeration in this configuration is obtained by a self-refrigeration system (open–closed cycle). High performance of the multi-stream heat exchangers, high recovery levels of the hydrocarbon liquids and low required compression power (in the internal refrigeration section) are three of most important characteristic of the proposed configuration. The effects of the mixed self-refrigerant flow rate and pressure on the performance of the process are discussed. Various values for feed composition are tested and the results show that the process can work efficiently with different feeds. In order to analyze the need of external refrigeration by a close or open cycle that is related to the composition of the inlet gas, a configuration with external refrigeration is designed the manner that it is similar with the purposed configuration in the separation section. 相似文献
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Leon van Schaik 《Architectural Design》2005,75(5):84-90
Does a notion of unfolding Modernism, enriched by a broadening of the cultural mix, stand up in contemporary Australia? Leon van Schaik cuts to the quick and questions Modernism's relevance for the antipodean itinerant condition. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
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跨国公司运营中的三资一体化特征分析——以必和必拓集团为例 总被引:1,自引:1,他引:0
"三资"(资源、资产、资本)是矿业企业经营勘查和开发活动的核心要素。各资源类跨国公司在成长及运营管理过程中,形成了各具特色的三资一体化模式。本文选取必和必拓集团作为探讨对象,通过对其在风险勘查、资本运作、资产管理、融资平台等一系列经营活动中的三资一体化特征进行分析,总结归纳出资源价值的重要发掘途径、三资一体化的重心、三资一体化的重要基础和企业成长发展的重要保障等关键内容,为我国矿业企业实现三资一体化运营和成长为跨国公司提供了很好的借鉴和参考意义。 相似文献
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连续循环阀气体钻井技术及其现场试验 总被引:3,自引:0,他引:3
目前气体钻井面临大出水地层生产时效低,中断循环后可能引起井壁垮塌、卡钻等井下复杂,充气钻井井底压力波动大、井控风险高等问题。为此,介绍了新研制的一种基于连续循环阀的钻井系统的技术原理以及现场试验情况。该系统主要由连续循环阀和地面控制系统两个部分组成,钻进中将连续循环阀接在钻杆上,接单根、起下钻时,通过连续循环控制系统切换循环通路,实现井下连续循环。在宁211井氮气钻井和月005 H1井充气钻井2口井现场试验的结果表明,接单根作业井底压力恒定,缩短了重新建立正常循环的时间,实现了接单根和起钻作业过程中的连续循环,初步证实了连续循环系统的可靠性与工艺的可行性。连续循环钻井技术在充气钻井过程中的试验成功,标志着该项技术从单一循环介质迈向了两相循环介质的新台阶,可为钻井液条件下的欠平衡井、窄密度窗口井、大位移井、长段水平井安全高效钻井提供新的技术手段。 相似文献
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Tugba Keskin Kubra Arslan Haris Nalakth Abubackar Cansu Vural Didem Eroglu Duygu Karaalp Jale Yanik Guven Ozdemir Nuri Azbar 《International Journal of Hydrogen Energy》2018,43(23):10666-10677
Trace elements are one of the important parameters for dark fermentative H2 production because they work as co-factors in H2 formation biochemistry. Lack or excess of trace element and its concentrations could be an important reason for the low yield of H2 production. In this study, the effects of 11 different trace elements (Fe, Ni, Zn, Co, Cu, Mn, Al, B, Se, Mo and W) were tested at two levels in terms of biohydrogen production from Fruit and Vegetable Wastes (FVW) with Biochemical Hydrogen Potential (BHP) Tests using Plackett-Burman statistical design. 1.1–2.8 times enhancement of biohydrogen production was determined with its addition. The most effective trace elements were found as Zn and Ni. In order to reveal the resident microbial flora, Denaturing Gradient Gel Electrophoresis (DGGE) analysis was carried out on all BHP effluent samples. Results of DGGE analysis, four microbial sequences evaluated as Clostridium sp., Clostridium baratii, Uncultured bacterium, Uncultured Streptococcus sp., and their similarity rates were 99%, 100%, 89%, 98%, respectively. 相似文献